Pressurized air is often used to disperse liquid and solid products. The products are often introduced into the air stream through various types of venturi arrangements which pull the product into the air stream. When a solid product, typically in the form of powder, granules or pellets, is dispersed, the supply of solid product often has a tendency to clog or pack up in the container holding the supply of the product; some sort of agitation of the product is often used to prevent this. Both mechanical agitators and pressurized air have been used to agitate solid products.